Leverage browser caching issue with already cached content
php,caching,browser-cache,amazon-cloudfront,google-pagespeed
The configuration you specify here controls how CloudFront caches objects, not how they are cached by browser. You still need to send Cache-Control header from origin to control browser caching.
HTML5 video tags not showing amazon videos
html5,video,amazon,amazon-cloudfront
The code you posted works perfectly. Are you sure the browser supports the video tag? Check http://caniuse.com/#search=video You should always aim to support most browser and unfortunately HTML5 is not well supported yet. You can provide fallback solutions inside the video tag. I.e. <video id="video1" controls width="270" autoplay> <source src="http://vidorabia.s3.amazonaws.com/2/testing%20-%2014.mp4">...
Cloudfront redirect www to naked domain with ssl
redirect,ssl,amazon-s3,amazon-cloudfront,amazon-route53
I found the solution thanks to this answer: Amazon S3 Redirect and Cloudfront In short: Cloudfront does not respect the redirection rules setup in S3 if the origin is just the bucket ID. Instead I had to set the origin to the provided s3 static website host name....
Weighted round robin dns between 2 Cloudfront distributions
amazon-web-services,amazon-s3,amazon-cloudfront,amazon-route53
Unfortunately what you are trying to do is not possible. CloudFront, or any HTTP server for that matter, only see's the host header of test.example.com. It has no idea how you got there, be it WRR DNS or hosts file, it only see's the host header. I'm not sure how...
How to add Cache headers to Cloudfront?
amazon-web-services,amazon-cloudfront
You need to add these headers (max-age or expires) on your origin. It is the origin that decides how long objects should stay in cache
Setting Asset Cache Expiration in Rails / Cloudfront / Heroku
ruby-on-rails,ruby,heroku,amazon-cloudfront
Set the response header To enable browser caching you must set the Cache-Control and the Expires response header. Debugging tip To see your existing cache settings, use your browser's debugger. For Chrome, while on any page in your app, open the debugger and look under: It's important to see what...
CloudFront strange behavior
caching,amazon-web-services,amazon-cloudfront
After many tests on Apache configuration and CloudFront configuration, i found that cookies where causing this behavior. Some cookies used by tracking systems change their values on each call and then cloudfront do not cache the request. To solve it, create a custom behavior for each type of path (backend...
What does the JSON for batch invalidation of a Cloudfront distribution look like?
amazon-web-services,amazon-cloudfront,aws-cli
You can generate sample JSON using the following command. $ aws cloudfront create-invalidation --generate-cli-skeleton | vi - Output: { "DistributionId": "", "InvalidationBatch": { "Paths": { "Quantity": 0, "Items": [ "" ] }, "CallerReference": "" } } ...
Would it be possible to point a number of cloudfront distributions to a single s3 Instance
amazon-web-services,amazon-s3,amazon-cloudfront
Yes, you can use single S3 bucket as an origin for multiple distributions.
how to specify asset_host in rails 4?
ruby-on-rails-4,amazon-s3,actionmailer,amazon-cloudfront,ruby-2.1
I solve this issue by putting these configuration in the block in config/environments/staging.rb Demo::Application.configure do config.action_controller.asset_host = Proc.new { |source| if source.include?('/assets') "d1xw0c7m8has5k.cloudfront.net" else "#{ENV['FOG_DIRECTORY']}.s3.amazonaws.com" end } config.action_mailer.asset_host = Proc.new { |source| if source.include?('/assets') "http://d1xw0c7m8has5k.cloudfront.net" else "http://#{ENV['FOG_DIRECTORY']}.s3.amazonaws.com" end } end and its is necessary to provide protocol with...
Multiple websites with Single CloudFront Distribution does not get routed
php,apache,amazon-cloudfront,amazon-elb
From your problem description and headers you have posted I think you need to configure CloudFront distribution to pass Host header to origin. Take a look here: http://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/header-caching.html#header-caching-web
Using Amazon S3 for iOS app storing images / audio files
ios,image,audio,amazon-s3,amazon-cloudfront
I recently built an app that moved photos back and forth between S3. I looked into using Amazon's SDK but it was just too bulky. Instead I used Matt Thompson's AFAmazonS3Manager. Worth looking into if you are building an app with AWS....
Cloudfront signed cookies and simultaneous access to multiple paths in s3 bucket
cookies,amazon-s3,amazon-cloudfront
You cant specify multiple paths in your policy. If you folder structure won't match the wildcard values you can use, you will probably need to generate signed cookies for each path and scope them accordingly. You can specify for what path a cookie will work for. When you Set-Cookie, specify...
Cloudfront URL vs S3 URL on AWS
amazon-web-services,amazon-s3,amazon-cloudfront
Yes, you need to reference the new domain/bucketname that cloudfront gave you when you setup the distribution, otherwise your requests will bypass cloudfront and go directly to S3. You can still use the S3 link, but that would defeat the purpose of having used cloudfront....
DNS name for S3 bucket folder
amazon-web-services,amazon-s3,amazon-cloudfront,amazon-route53
You can create a distribution for a specific folder, was just announced in mid-december: Amazon CloudFront Now Allows Directory Path as Origin Name- Date: December 16, 2014 Details: When you specify the origin for a CloudFront distribution - the Amazon S3 bucket or the custom origin where you store the...
Where are my assets files stored?
heroku,ruby-on-rails-4,amazon-s3,cdn,amazon-cloudfront
If your files are being served from your CloudFront distribution and they are not being pulled from your S3 bucket "assets" as you previously thought, then you probably have set up your CloudFront distribution to use a custom origin such as your web server (S3 buckets are the normal/standard origins)....
Access protected S3 bucket using CloudFront
amazon-web-services,amazon-s3,amazon-cloudfront
It's all in the docs. http://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/private-content-signed-urls-overview.html You also have to properly configure the interaction between Cloudfront and S3. http://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/PrivateContent.html If you are a programmer, you will also find it interesting and important that Cloudfront uses a different set of base64 rules than S3. Instead of percent-encoding the unsafe characters +...
Serve protected assets through CDN
Amazon CloudFront also offers Serving Private Content through CloudFront to address your use case: Many companies that distribute content via the Internet want to restrict access to documents, business data, media streams, or content that is intended for selected users, for example, users who have paid a fee. To securely...
How to get Cloudfront subdomain from the request on the custom origin?
amazon-web-services,amazon,amazon-cloudfront
You can configure CloudFront to through pass Host header to the origin. It is described here: http://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/header-caching.html. Note that in this case it will also be included into the CloudFront's cache key, so use it if you plan to serve different content for different values of Host header.
Cross Domain CORS and Images
html,amazon-web-services,amazon-s3,cors,amazon-cloudfront
CORS is a policy enforced by a browser. Its not going to prevent users from downloading images from your cloudfront distribution. You have two options. Make all your files private and provide access via signed urls. Cloudfront wont really cache images in this case however. The other option is to...
Microsoft Smooth Streaming on demand without a web server
iis,amazon-s3,amazon-cloudfront,smooth-streaming,smooth-streaming-player
Alright, I found an answer! This tutorial explains it all. http://howto-phpjsjqueryawss3ec2cloudfrontfacebooktwittergoogleawsapis.com/how-to-smooth-stream-microsoft-smooth-streaming-files-on-amazon-cloudfront-without-a-web-server/...
How to invalidate a file(to be refreshed) served from Cloudfront CDN via Java AWS SDK?
java,amazon-web-services,amazon-cloudfront
import com.amazonaws.services.cloudfront; import com.amazonaws.services.cloudfront.model.CreateInvalidationRequest; import com.amazonaws.services.cloudfront.model.Paths; import com.amazonaws.services.cloudfront.model.InvalidationBatch; AmazonCloudFrontClient client = AmazonCloudFrontClient(); Paths invalidation_paths = new Paths().withItems("/path/to/invalidate/foo.jpg", "/path/file2.txt"); InvalidationBatch invalidation_batch = new InvalidationBatch(invalidation_paths, "unique_id_like_a_date");...
Can I/Should I add Cloudfront to my webservice running on elastic beanstalk
caching,amazon-web-services,elastic-beanstalk,amazon-cloudfront
I always put cloudfront in front of any solutions I deliver on AWS. In response to your specific questions: Most likely yes, it would off load some of the work that may go to an EC2 instance so it might prevent an extra instance from spinning up sometimes. Maybe, maybe...
Is it possible to add logic to CDN
I think what you are after is User Agent based caching, like vary: User-Agent. In theory, a server provide Cache service can definitely do so, however, as far as I can tell CloudFront and most of other major CDN providers don' support so. The basic reason is very straightforward that...
AWS Ruby SDK v2, Cloudfront list_distributions, iterate over the results
ruby,amazon-web-services,amazon-cloudfront
I got a reply from a thread in the aws discations forums that say that it's a bug in the sdk and it should be resolved in the next release. link to the issue
Grunt module(s) to upload all static assets to S3 / CloudFront, replace paths, and invalidate old assets
node.js,express,amazon-s3,gruntjs,amazon-cloudfront
Invalidating CDN assets is a Bad Idea ®. In CloudFront, it may take up to 15 minutes to complete - that would be adding 15 minutes to your deploy. Also, some browsers may hold old files because the URL is the same. Instead, you should probably version you static assets...
Using amazon cloudfront to stream on demand without using s3
amazon-web-services,amazon-s3,amazon-cloudfront,rtmp,ondemand
This is not possible. See the second sentence in the manual: http://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/StreamingDistributionS3Origin.html
Why are two requests with different clients from the same computer cache misses on cloudfront?
curl,amazon-cloudfront,http-caching
The reason you are seeing this behavior is because your requests are different. To give you some background, Cloudfront cache varys based on the http accept-encoding header. In your first example, in your browser, you are sending the value of gzip. With your curl example, by default, you are not....
Amazon Cloudfront removes Referer header
In today's newsletter amazon announced that it is now possible to forward request headers with cloudfront. See: http://aws.amazon.com/de/about-aws/whats-new/2014/06/26/amazon-cloudfront-device-detection-geo-targeting-host-header-cors/
htacess rewrite require www with cloudfront CDN support
.htaccess,mod-rewrite,redirect,amazon-web-services,amazon-cloudfront
I've forgot about this question already, but I've fixed the problem. I can't remember exact steps, what I've done, but now i have a subdomain for static contents - js, css etc. it points to same directory as it would be normal domain. eg: http://s.oisie.com/img/oisie.png is same url as http://www.oisie.com/img/oisie.png...
Multiple Cloudfront Origins with Behavior Path Redirection
amazon-web-services,amazon-s3,amazon-cloudfront
Yes, the patterns have to exist at the origin. CloudFront can prepend to the path for a given origin, but it does not currently have the capability of removing elements of the path. If your files were in /secret/files/ at the origin, you could have the path pattern /files/* transformed...
How to install SSL on CloudFront correctly?
ssl,amazon-s3,ssl-certificate,amazon-cloudfront
The certificate chain file is a "chain" of trust. It is a combination of the contents of all (usually) of the provided *Trust*.crt files, and they need to be combined in a specific order, including the begin/end lines found in each file. All of the the .crt files have a...
Static Site Deployment in AWS S3 with CloudFront
amazon-web-services,amazon-s3,amazon-cloudfront,amazon-route53
You will want to make sure that you are setting your default root object in Amazon S3 and that your origin is the S3 Website endpoint. Example origin: www.example.com.s3-website-us-east-1.amazonaws.com http://docs.aws.amazon.com/AmazonS3/latest/dev/website-hosting-custom-domain-walkthrough.html...
Storing user submitted images
node.js,file-upload,amazon-s3,amazon-cloudfront
i think you can use knox for you task, for example. First you need create "class" with s3 api. Do this with knox: var s3 = function(args){ this.client = knox.createClient({ key: '<api-key-here>' secret: '<secret-here>' bucket: 'learnboost' }); } s3.prototype = { getImage: function(userId, imageId){ var d = Q.defer(); var image...
Restricting Time access for AWS Cloudfront
No, the closest to what you want is ability to sign URLs which allows to limit how long URL is valid. But unfortunately: RTMP distributions: CloudFront checks the expiration time in a signed URL at the start of a play event. If a client starts to play a media file...
Rails 4 App - Heroku / Cloudfront - Assets not serving from origin properly
javascript,ruby-on-rails,ruby,heroku,amazon-cloudfront
Add gem 'rails_12factor', group: :production # Helpful for rails 4 assets on heroku And in /config/environments/production.rb config.assets.compile = true This should work...
Why is my newsletter form not working on Amazon CloudFront?
javascript,php,amazon-web-services,amazon-ec2,amazon-cloudfront
Please make sure your CloudFront distribution is actually configured to handle POST/PUT requests. Take a look here for details: http://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/distribution-web-values-specify.html#DownloadDistValuesAllowedHTTPMethods
loadHTTPProvider error on wowza
amazon-cloudfront,http-live-streaming,wowza
I'd first confirm that you've placed the custom http provider jar file in your production environment (lib folder) along with any other jar files that it may reference. Then restart Wowza and try again. If you should experience any further trouble, valid license holders can send support requests to support[at]wowza.com....
Rails + AWS CloudFront + CORS for AngularJS HTML templates
ruby-on-rails,cors,amazon-cloudfront
I've been asked for this solution a couple times, so I thought I would post what worked for us here. It seems that Rails will set the CORS headers correctly for CSS and JS files only. However, you can use the rack-cors gem to set custom headers for resources. We...
Cookies set, but not sent to Cloudfront
ruby-on-rails,cookies,amazon-web-services,amazon-cloudfront
This is normal: each cookie has an associated domain and for each request the browser will only send cookies that match the URL the request is being made for. Furthermore you cannot set cookies for arbitrary domains - if your application was on example.com then it can set cookies for...
SSL certificate handshake exception aborts DownloadManager image download from CloudFront
Please check this CVE, I think it deals with your issue: http://aws.amazon.com/security/security-bulletins/CVE-2014-3566-advisory/ It means that by default SSLv3 is disabled because it is not considered secure...
which ssl certificate is the right one for aws elastic load blancer and cloudfront? ssl certificate compatibility
ssl,amazon-web-services,https,amazon-cloudfront,amazon-elb
I would recommend taking a look at the documentation [1] that discusses the requirements/limits. The big difference is for cloudfront, you need set your path to /cloudfront/. http://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/SecureConnections.html#cnames-and-https-requirements ...
What is the difference between Canned Policy and Custom Policy?
Yes, a canned policy can convey only a specific subset of the attributes of a custom policy, but the distinction between the two is more significant. When you use a canned (pre-defined) policy, the contents of the resulting canned policy document are so deterministic and predictable -- from the elements...
Amazon CloudFront not consistently returning 304 (Not Modified) for unchanged static content?
asp.net,caching,amazon-web-services,amazon-ec2,amazon-cloudfront
The answer was found in an obscure sentence written in a seemingly unrelated piece of Amazon documentation: When you configure CloudFront to forward cookies to your origin [...] If-Modified-Since and If-None-Match conditional requests are not supported. Strange, but indeed the reality of the situation is far worse; It's not that...
What is wrong in my amazon autoscalling?
This is probably the key paragraph: When you customize the termination policy, Auto Scaling first assesses the Availability Zones for any imbalance. If an Availability Zone has more instances than the other Availability Zones that are used by the group, then Auto Scaling applies your specified termination policy on the...
What should I set for origin domain name when using Cloudfront, EB and Route 53?
amazon-web-services,elastic-beanstalk,amazon-cloudfront,amazon-route53
Turns out that although it is not listed I can indeed just set it the CNAME Ive set in Route53, and it works
Why is CloudFront working via one CNAME record but not another?
amazon-web-services,elastic-beanstalk,amazon-cloudfront,amazon-route53
The problem was that although I modified the search.widget.com CNAME to point to drvevtora80lk.cloudfront.net I forgot to add search.widget.com as an alternate name within my Cloudfront distribution, adding that and it now works.
Unable to decode CORS gzipped content from EC2 via Cloudfront
amazon-web-services,gzip,amazon-cloudfront
Yes, you're missing something. Read the response headers of the last response. Last-Modified: Wed, 06 May 2015 14:36:32 GMT ETag: "7a92919df6117827de9474851afe06c0" Age: 1261 X-Cache: Hit from cloudfront This is a CloudFront cache hit, and CloudFront fetched this object from S3 20+ minutes before you requested it ... and this version...
Cloudfront stream only part of the video
video,amazon-web-services,video-streaming,amazon-cloudfront,rtmp
No, CloudFront does not support this functionality. You will need to point player to the different video in this case.
Cloudfront traffic cheaper than S3? [closed]
amazon-web-services,amazon-s3,amazon-cloudfront
There are also charges for number of requests. As far as serving out content goes (and for US East), in S3 it's $0.004 per 10,000 GET requests, while CloudFront is $0.0075 per 10,000 HTTP Requests and $0.0100 per 10,000 HTTPS Requests. The info is listed under the Request Pricing sections...
s3cmd to set correct content type for image/jpeg
amazon-s3,amazon-cloudfront,s3cmd
s3cmd has recently (as in, this past weekend) fixed this, but the code is not yet upstream. Please try with this branch: https://github.com/mdomsch/s3cmd/tree/bug/content-type With a little more testing, this will get merged into upstream. Then, your command should work exactly as you expect. -mdomsch, s3cmd maintainer...
Use Amazon S3 and Cloudfront for intelligently caching webapges
java,amazon-web-services,amazon-s3,amazon-cloudfront
OP says: they can sometimes be large up-to 20mb Since the volume of data you serve can be pretty large, I think it is feasible for you to do this in 2 requests instead of one, where you decouple the content generation from the content serving part. The reason to...
How can I tell if CloudFront has an object stored in cache?
caching,amazon-web-services,amazon-cloudfront
There is no API call to check the contents of a CloudFront cache. (Actually, there's more than once cache, since objects could be cached at any of the 50+ CloudFront edge locations.) An alternative would be to modify your web app to serve content that refers to a newer version...
Access Denied (403) from AWS Cloudfront Signed Cookie on Rails backed app
ruby-on-rails,amazon-web-services,amazon-s3,amazon-cloudfront,amazon-signed-cookie
I solved myself. I had three defects, and now it works well after correcting them. First, I changed expires to policy. 'CloudFront-Expires' => expiry.utc.to_i, to 'CloudFront-Policy' => safe_base64(raw_policy), Actually, I had used policy(custom) instead of expires(canned). During my tring, I had changed. But I don't know why expires version doesn't...
AWS CloudFront Behaviors Issue
amazon-web-services,amazon-cloudfront
That setting doesn't overwrite the cache-control header - it just affects how long cloudfront (not the browser) caches objects. In any case it is just a lower bound - cloudfront uses the maxage value (unless it is less than the minimum ttl) This table summarizes the behaviour but in short...
Upload a file to Amazon S3 with NodeJS and S3FS/multiparty
node.js,amazon-web-services,amazon-s3,amazon-cloudfront,s3fs
i found the solution myself ,the file name i was sending to write file was wrong , i only replaced \ with / when getting the file name from temp path. var filePath= 'home\ubuntu\www\html\sampleProject\public\files\myfile.jpg'.replace(/\\/g, '/'); var fileName = filePath.substr(filePath.lastIndexOf('/')+1,filePath.length-1) ...
How can I cache to 1 minute with S3 and CloudFront and Write-S3Object
amazon-web-services,amazon-s3,amazon-cloudfront,cache-control,aws-powershell
Here's a nice primer for the Cache-Control header. You need the header to look like this*: Cache-Control: public,max-age=60 The cache-control header uses seconds, not milliseconds. 'public' just means "it's okay to store this on a CDN", basically. I believe this will work in your initial Powershell command: -HeaderCollection @{"Cache-Control" =...
Refresh image in CDN immediately after upload to S3 with same file name
amazon-web-services,cdn,amazon-cloudfront
You'd want to store a count of how many times it has been changed and use something like <userId>.jpg?v=2 on your site. You'd have to turn query strings on for the CloudFront distribution. Without a filename change or query string change, you'd have to use a CloudFront invalidation, which will...
How can I replace my CloudFront distribution with another without user downtime
amazon-web-services,amazon-cloudfront
You actually don't have to wait for the distribution to be deleted to reuse the cname. I do something similar. create a new distribution that has identical settings as my current one, minus the cname settings remove the cname from the old distribution, save immediately add cname to new distribution...
Text Track from origin has been blocked from loading and Heroku Django App
django,cors,amazon-cloudfront,django-cors-headers
Please check this: stackoverflow.com/questions/12358173/…. Might be exactly the answer you are looking for. Alternatively - please confirm it works when you hit S3 directly & provide curl output from S3
How to put object to S3 via CloudFront
java,amazon-s3,amazon-cloudfront
Data can be sent through Amazon CloudFront to the back-end "origin". This is used for using a POST on web forms, to send information back to web servers. It can also be used to POST data to Amazon S3. If you would rather use an SDK to upload data to...
Amazon s3 or cloudfront [closed]
Amazon CloudFront is a content-distribution network that acts as a caching layer for web content. When a CloudFront distribution is created, you receive a special URL that is used to refer to traffic on CloudFront. When this URL is resolved, AWS will return an IP address that points to the...
Can I configure Cloudfront so its split traffic to two origins
amazon-web-services,amazon-s3,amazon-cloudfront
Yes, you can... and if you want to use CloudFront for all of the content, there's no reason that comes to mind why you wouldn't use a single distribution. As long as you can sensibly specify which path patterns go to which origin, it's pretty straightforward to configure. http://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/distribution-web-values-specify.html#DownloadDistValuesPathPattern...
“You need to give a SHA parameter” error when serving Dragonfly images through Cloudfront
ruby-on-rails,amazon-cloudfront,dragonfly-gem
By default, CloudFront does not forward query strings to the origin. Have you verified that you have query string forwarding enabled?
Amazon CloudFront: How to get monthly cost breakdown per distribution?
amazon-web-services,amazon-s3,amazon-cloudfront
The last field of the Detailed billing report is ResourceId, which appears to contain the distribution ID or alias for the distribution. I've seen both "ID" and "alias" listed for the same distribution, so I don't know why.
W3 Total Cache: .woff and .otf font files not uploading to CDN?
wordpress,caching,fonts,cdn,amazon-cloudfront
Figured it out thanks to GNASCHENWENG. Turns out the file-extension separators after .woff and .otf were commas, when they needed to be semi-colons: Fonts uploaded successfully to CloudFront now....
How do you set a default root object for subdirectories for a statically hosted website on Cloudfront?
amazon-web-services,amazon-s3,amazon-cloudfront
Unfortunately, the answer to both your questions is no. 1. Is it possible to specify a default root object for all subdirectories for a statically hosted website on Cloudfront? No. As stated in the AWS CloudFormation docs... ... If you define a default root object, an end-user request for a...
netstream no working on adobe air - amazon s3 - signed cloudfront
android,actionscript-3,air,amazon-cloudfront,netstream
I tested your stream in my android device and it's working fine, and I think that your forgot to use the params with your stream, so you can do like this : var url:String = 'rtmp://s1p2w2yhnipjkt.cloudfront.net/cfx/st', // or rtmp://s1p2w2yhnipjkt.cloudfront.net:80/cfx/st stream:String =...
How does one find real Host when using Cloudfront?
amazon-web-services,amazon-cloudfront
Good news- cloudfront supports host header forwarding now. It's listed very deep in the documentation: Host [header]: CloudFront sets the value to the domain name of the origin that is associated with the requested object. Presumably, all you need to do is ensure header forwarding is enabled in the Default...
Is it impossible to use AWS CloudFront for downloading my private image on S3?
ios,amazon-web-services,amazon-s3,amazon-cloudfront,aws-sdk
If you want to serve private content via CloudFront, you will find this doc useful http://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/PrivateContent.html. Currently the AWS SDK for iOS doesn't support CloudFront directly. You need to manually sign the request. A related question is asked on AWS forum https://forums.aws.amazon.com/thread.jspa?messageID=336955.
Cloudfront, files from member area
amazon-web-services,amazon-cloudfront
I guess you are talking about serving private CloudFront content to your member, but not to public ? If yes, AWS supports that in CloudFront. But you need to do either "signed url" or "signed cookie" method to access the cloudfront assets. ( of course, you need to setup your...
Does using CNAME with Amazon CloudFront cause extra charge?
amazon-web-services,cdn,amazon-cloudfront,cname
As far Amazon documentation says, CNAME is free. Now your actual confusion is, why services like Dropbox or others do not use Custom CNAME? The Answer is lookup resource. Each time someone ( A browser perhaps ) look for the file, it makes a lookup to find it's host. Then...